Chemoprevention for Breast Cancer

Cancer chemoprevention is defined as the use of natural, synthetic, or biochemical agents to reverse, suppress, or prevent carcinogenic processes in neoplastic diseases. Although the precise mechanisms that promote breast cancer are not fully understood, several recent clinical trials suggest that chemoprevention is a rational and attractive strategy for selected high-risk populations in a prophylactic setting. Conventionally, endocrine interventions using selective estrogen receptor modulators and aromatase inhibitors have already been applied clinically in high-risk populations. In particular, the chemoprevention approach for BRCA germline mutation carriers is drawing attention as an alternative option to invasive prophylactic mastectomy. Although the evidence from prospective clinical studies was limited, this review aims to provide an up-to-date overview of the biological mechanisms and the efficacy of various chemopreventive agents, including new promising candidates that target BRCA deficiency, and discuss future challenges and prospects for breast cancer chemoprevention.